Vertical pressure plate food freezing machine



March 24, 1953 l. H. POLK 2,632,312

VERTICAL PRESSURE PLATE Eoon FREEZING MACHINE Filed Feb. 1e, 194e 4 sheets-sheet 1 FIG. l.

lil |11 lim 35 i* N lil 45M [Il lllsll' March 24, 1953 1 POLK 2,632,312

VERTICAL PRESSURE PLATE FOOD FREEZING MACHINE Filed Feb. 16, 1948 4 Sheets-Sheet 2 FIG. 3.

Il 5o |NvENToR I vISA/IC H. POLK l2 I 2 I I 24W VMM ATTORNEYS March 24, 1953 FOLK 2,632,312

VERTICAL PRESSURE PLATE FOOD FREEZING MACHINE Filed Feb. 16, 1948 4 SheeS-Sheet C5 We" m4 )IMM ATTORNEYS March 24, 1953 H FOLK 2,632,312

VERTICAL. PRESSURE PLATE FOOD FREEZING MACHINE Filed Feb. 16, 1948 4 SheecS-Sheet 4 FIG. Il.

ATTORNEYS Patented Mar. 24, 1953 UNITED STATES PATENT OFFICE VERTICAL PRESSURE PLATE FOOD FREEZING MACHINE Isaac H. Polk, San Jose, Calif.

Application February 16, 1948, Serial No. 8,553

1 12 Claims.

This invention has to do with apparatus and methods for the quick or sharp freezing of food, particularly food that is packaged in paper cartons or containers before it is frozen.

Ordinarily, food in paper packages is frozen by conduction with the packages disposed in contact with refrigerated surfaces, in order to guard against penetration of the permeable container as might take place Were the packages subjected to a brinel spray or bath to freeze the contents. In the preservation of comestibles in containers it is necessary to provide an air or vacuum space in the containerto allow for expansion of the comestibles which occurs during freezing. This air or vacuum materially retards heat transfer when it is interposed between the conduction surfaces and the product, since air or a vacuum is a very poor heat conductor. Moreover, it is Iwell known that the thickness of a substance to be frozen determines the time required to completely solidify such substance, with all other factors equal, and the time required to freeze a substance varies approximately as the square of the thickness of such substance, all other factors remaining constant.

In my copending application for patent for Tunnel Freezing Apparatus and Method, filed August 21, 1946, Serial No. 691,962, I disclose vertically disposed freezing surfaces permitting the packages to be so arranged with respect to the force of gravity and the freezing surfaces that no air or vacuum is interposed between the product and the conduction surfaces, thereby increasing the rate of heat transfer, increasing the area of conductive contact, and reducing the thickness of the material to be frozen to a minimum. An important object of this invention is to provide improved apparatus for accomplishing this.

Present 'apparatus in commercial use, with which I'am familiar, has several disadvantages. A major disadvantage or difficulty with such apparatus is the fact that it is impossible therewith to so dispose the packages to be frozen with respect to the force of gravity and the conduction surfaces as to obtain maximum heat transfer. Another disadvantage with present apparatus is the tendency of the packages to adhere or freeze to the conduction surfaces due to the presence of ice or frost thereon, with the result that the packages must be broken loose after the freezing cycle. This continually results in rupture of an appreciable percentage of the packages, causing loss of food and loss of time and labor required to clear the apparatus. Another disadvantage in present apparatus is the fact that since packages tend to adhere to the conduction surfaces lwhen any ice or lfrost is present, and since ice serves as insulation when disposed between the packages and conduction surfaces, it is necessary, periodically, to defrost the machine, with a consequent loss of production. Another disadvantage of present apparatus is theA difficulty presentedby the fact that the -designof present apparatus precludes the 4application of automatic loading and unloading of the packages. Y An object of this invention is to povide'novel apparatus for the sharp freezing of packaged lfood by conduction freezing through intimate contact of thepackages with refrigerated, highly' heat conductive surfaces which obviates the par-y ticular disadvantages, of present apparatusn'oted above. A particular object is to provide appa-v ratus of this type in which the refrigerated surfaces are verticallyarranged and the packages are maintained in intimate pressure engagement therewith Iduring the freezing cycle. In this connection, it is an obj ect to provide apparatus which allows for any expansion of the product within the container during freezing while maintaining the plates in ,sufficient pressure engagement therewith to insure maximum heat transfer without distortion of the container.

Another object is to provide a new and improved conductionor freezing plate construction which enables the use of4 thev so-calledv flooded system of refrigeration with the plates forming the evaporator for the system. A particularobj ect is to provide a plate Ywith'refrigerant header passages along opposite edges and a plurality of connecting passages therebetweeny whereby, when the plateJ is vertically disposed with one header passage at the upper edge and the otheratthe lower, the lower passage may be used as an inlet header to feed the connecting vertical passages and the other as an outlet header to conduct fluid away from the vertical passages.

A further object of the invention is to provide a method and apparatus for conditioning the conduction surfaces to minimizeand substantially prevent the formation of frost thereon withv the consequent freezing of the packages thereto and to remove any ice or frost that may form. on the surfaces. A particular object is the provision of a machine embodying vertically disposed freezing plates between which the packages of. foodare placed to freeze them in which means is provided for periodically applying anti-icing uid to the surfaces of the plates between freezing cycles without raising the temperature of the plates.

Another object is to provide, 'in a machine having laterally spaced vertically disposed freezing plates, movable means for loading and unloading the packages of food and forsimultaneously applying an anti-icing fiuid to and shortly thereafter removing it from the plates. A further object is the provision of an anti-icing fluid applicator means designed to apply and evenly spread the uid on the surfaces of the plates in one motion and to thereafter? remove the: fluid in ail second motion, theapplicator also being designed to-act as an elevator for charging the machine with packages and discharging packages therefrom. A still further object is to provide-suchanapplif. cator which entirely encloses the anti-icing fiuid'. and the plate area during application of the fluid,

thereby preventing contamination of the packaged food.

Another object of the invention is to provide, in a machine of the type indicated, a fluid pres-Y sure operated means forfmoving the plates latemily 111.120 pressure.- engagement with. food nackaeea between. the7 plates... for. maintaining; the plates. in pressure engagement with` the pack gesl during thefreezingl Cycle., and for moving the.- plates...- awav from the.I packages in. coordinatonfwith; a verticallymovable elevator for removing the packagesA from the machine. It is atparticular object toprovide means-to coordinate the movement ofv the elevator and plates during discharge of theffood packages through a fluidpressure system. inI such a way that. the movement of these. parts is; dependent upon. the resistance .to movementv thereof caused. by the packages. whereby any` packages which mayv adherev tothe, plates may be. safely loosened. for dis,` charge..

A further-object is. thev provision of a flexiblesuspension means for the plates in. combinationzwith a package. elevator andi means for laterally moving the. plates. whereby limitedl vertical.independent-movement of the'plates is per.- mitted during unloading, of. thel machine to as. sist in ryuptur-ing` any adhesions` that may exist betweenk the plates and packages.

v These-and other objectswill be apparent from the,V drawings and. the following: description thereof. In the drawings:

F-igr. 1 isa side. elevational view of a machine embodying the invention.;y

Fig... 2 is: an.end elevational. view ofV the machine of Fig-1, the view being online 2 2. of Eig@ 11;l

Eiajais avian. view or the machine1 of; nig 1,;

Eig.; 5,- is; an enlarged.. view of the uppern end pantie!! of one plate.y showingv the suspension means therefor:

Eig. 6.is a perspective View, partly broken away, of. aV refrigerant plate;

Fig. 7 isv a fragmentary sectional view onI line 1-1 of Fig. 6;

Fig'. 8 is a perspective view.- of an. anti-icing fluid applicator member;

Fig.. 9 is an enlarged sectional'. view. online Eli-9. of Fig. 8;

lig.V 101 is, an. enlarged fragmentary plan` view of one of the refrigerantA plates` and showing the end seal;

Eig. Il'I is a schematic View of the apparatus; Fig. 12 is a schematicview of the; control valvej in one position; and

Fig; 13is a schematic, view of the control valve in' anotherposi-tion. Y

More particularly describing thev invention, reference numeral" |01 generally indicates the frame. of a machineY embodying the invention.

The frame may include longitudinal base channels l2 and suitable cross members I3. Extending upwardly from the base are four corner posts I4 which support longitudinal upper rails IG, intermediate rails I1, and any suitable number of cross members, including the two upper end cross members I8.

Suspended from the frame are whatwill be termed; conduction freezing;r platesv consisting of ay central-'or inner plate 2B and outer plates 22. For simplicity of illustration only three plates are shown; however, it will be understood that any7 desired; number of plates may be provided in a. given machine. The outer plates are provided with a layer 23 of heat insulation which covers-theouter sides and the edges of the plates. The. edgef. the, inner plate may also be covered with insulation, indicated by 23'.

Briefly, as will later appear, rectangularly shaped packages of foofd 25 (Fig. 4) are placed between, the' plateswith their least dimension: at right angles tov the plates, after whichthe'plates arer caused to be, moved laterally into. pressureA engagement with the; packages. therebetween', Pressure is. maintained on. thev packages during freezing of the contents. Subsequently, the packages are removed. andthe machine reloaded;

Preferably, the freezing plates. are resilientlv suspendedfrom the frame in amanner. to` permit limited. individual. vertical. movement thereof` in order to assistinrupturingany adhesions whichmay form between` the packages. and. the. plates during the.. freezing cycle. In the form. of. the invention illustrated, the plates are provided` r with. a, suspension means at each. end. generallyl indicated by. numeral 2S.l (Fig. 5.).. This means. includes a roller. 2;] mounted in. hanger Z8 terminating in a. headed stem29. received. in a housing 35 mounted on the plate. A compression spring 3i, is interposed' between the headed, end of the stem and the housingY tobear the weight of the plate. The rollers 21. ride on rails 32 mounted on` the longitudinally extendingv upper`= rails Hiv of. the frame.

It will be apparent that with this construction the plates are mountedffor limited verticalmovement and; that they also may. move laterally; Means. are provided for limiting and controlling lateral. movement of the outer plates 22. Refer,-` ring particulary to Fig..3, each of the outer platesl is provided with` a yoke assembly which comprises. a pair; of arms 35 pivotally mounted. at. their. outer ends. to the frame. at. 36.. The inf. ner endsL of the arms are operatively attached t0 a. piston 3.8 by a flexible connection. itil. Ine termediate their endsr the arms are flexibly. con-.fY nected, to adjustable. posts 42. mounted on, the plates. Cylinders 43 house the pistons` 38, which are double acting, provision. being made for selectively connecting the ends of the cylinders to. a source, of pressure fluid whereby the plates may be moved in orout. The movement of theplates laterally by this apparatus will be. de. scribed' later.

Referring to Figs; 6*v and' 'l'. which illustrate the construction of the plates, eachplate consists of a body provided with'V a lower or inletI header passage 45 along its lower edge portion, an upper or outlet header passage 46 along itsupper edge portion and a plurality of connecting passages 48Y across the plate whichY extend vertically in the suspended plate. The; plates. are constructed of a highly heat conductive ma'.- terial, preferably metal. Various. constructions may be.; used te provide.. the` aiorementioned.

By constructing the plates with a header along' the bottom and another along the top connected by a plurality of vertically extending passages, the plates may be usedy as an evaporator in a flooded system of refrigeration, such as where ammonia is used. The lower header of each plate may be connected to a separator 58 by exible tube 59 leading to a sub-header 60 fed by conduit 6|. A pipe 62 feeds the separator from a sourcev of liquid ammonia or other refrigerant supplied by a compressor, not shown. The upper header of each plate is connected to the upper end of the separator 53 through the mediuml of a flexible tube 64.

As previously indicated,-one of the greatest difliculties in the commercial sharp freezing of4 food in paper cartons or packages by the con-Y duction method is the tendency of the packages to freeze to the freezing surfaces with the result that it is difficult to automatically rupture 'theadhesions between the surface and the package without damaging the packages. a large percentage of the packages are broken, and a considerable loss is incurred. The adhesions between the packages and the freezing surfaces are caused largely by the presence of moisture on the freezing surfaces, or on the packages.

It is a feature of this invention that between successive loadings of the machine the surfaces of the plates are conditioned to prevent, insofar as possible, any formation of ice or frost on the surfaces and to remove any frost or ice that may form thereon. In order to accomplish this, means are provided for applying an anti-icing fluid to the surfaces of the plates as the packages are removed from the machine and for substantially removing this fluid and any resulting melted ice or frost or slush as the machine is loaded with a new charge of packages.

This means includes what will be termed applicators 66, one being provided for each space` between plates. The applicatorsv are mounted at the upper ends of piston rods S8 by a connection 69 permitting limited universal movement of the parts. Piston rods 68 extend upwardly from double acting pistons 'l0 (Fig. 11) contained in cylinders 'll pivotally mounted on a base part 'l2 of the frame.

The applicators each comprise a framework supporting a pair of vertically spaced wipers and a fluid distributor pipe therebetween having a suitable spray heads. More particularly, each applicator includes a pair of vertically spaced channels 'I5 and 16, a pair of flexible wipers Ti and 78, and a pair of inner straps I9 and 80 secured to the respective channels by rivets 8| and serving to mount the wipers. Intermediate end uprights 82Vconnect and support the members 19 and S0 in spaced relation. Pedestals 83 serve to support a fluid distributor pipe 84'which is secured at` its ends to` uprights 82. This pipe isprovided with a plurality of suitable spray Consequently,

heads 85. MountedA on the upper channel 16 is a member 81 providing a flat surface 88 which serves as a floor upon which the packages of food are supported during loading and unloading of the machine.

Means may be provided for sealing the ends of the wipers in the form of end closures 89 (Fig. 10) of tubular form joined to the wipers and 18 and being of a flexible resilient material such as a rubber-like composition.

contracted as shown by the full line position of the elements in Fig. 10, the broken lines showing the normal position occupied when the plates are expanded.

The distributor pipe 84 is supplied with-fluid from a reservoir 9] (Figs. land 11) through the medium of a piston-cylinder pump 9| and tubing 92' including flexible section 92. A tube 94 connects the reservoir and the pump and the tubes 92 and M are each provided with a check valve, indicated respectively by 95 and S6. 'TheA piston of the pump is connected to an applica` torby a, linkage which includes a lever 98 piv otally mounted on the frame at 99 and yconnected to the piston at lili). a link lever.

|62 connecting an applicator and the Upon downward movement of the applicator a charge of anti-icing fluid is drawn into This is discharged upon upward'A movement of the applicators. A trough Illlljlo-v the pump.

cated under the plates serves to catch fluid and slush removed from the plates, a tube |05 leading from the trough to the supply reservoir 90.

Preferably the lower wiper (1l) is made more flexible than the upper (18) so that, as the applicator rises and fluid is sprayed on the plate surfaces, the lower wiper will serve to evenly distribute the fluid Without removing it from the plates. As the wiper moves down, the upper` and stiffer' wiper will substantially remove theV pistons 'l0 and the pistons 3B which causes lateral,l

movement of the plates includesa reservoir and a pump which may be driven in any suitable manner by a motor H2. The pump is connected to the rservoir by an inlet pipe` ||4. On the discharge side `ofthe pump pipe 5 leads to a pressure regulator valve A|||i which in turn is connected by pipe Hl to a ve port valve H8. Leading from one port of the valve is tube IZ communicating with the inner ends of cylinders B3 and the lower ends of the ap.- plicator cylinders On the opposite side of the valve is a tube |22 which connects with the outer ends of cylinders 43. |23, leads from the valve to the upper ends of the applicator cylinders 1|.

Assuming valve ||8 to be in the position in which it is shown in Fig. 11, pressure fluid is supplied to the outer ends of cylinders 43 causing the plates 22 vto be moved into `pressure en-A gagement with the packages 25. .Withlvalve ||8 in the position in which it is shown in Fig. l2,

pressure uid is supplied tol the lower ends'of These elementsf readily conform to the plates when the same areV This lever is operated by Another tube,

A discharge liner |25 leads` from the fifth port to the reservoir..

a the apnlicatolrevlinders- H amlfthefnner ends-f' cylinders; 4i;. 'IS- his will resultin upward move-v ment: o f the.v app.Heaters..` Outward. movement. 0f; @chistes-2 2;

With the valve Il moved to theposition of Eig.-

pr-essure fluid. is supplied tothe upper ends of, therapplicator cylinders Li-l and the outer,y ends.. of' cylinders 43. However, pressurein thesec latter cylinders isv ineffective to move'the plates. until; the applicators. havereturned to; normal; lowerrnost position where; they engage-trip levers. liausing latchesv I 31;' toV disengage-catches 33 permitting; inwardmovementof the plates intov pressure; engagement. with: the packet-iee- In the operation of the machine, asspming thatl tba meehlne is... empty and; that. the.; valve.v llt.y iS inthe.. eeitionlirrwhienitfis s heWnyFie- 1.2,.. pressure fluid will lee-supplied.: te.v the.; IQWer; ends.. cf-the applicator cylinders il, and the inner ends, of.` cylinders 43,-, the plates being spread apart o r fnrpandedA and latched in expanded position by latches. 1.3i.. The machine. is. thenlteady. to be. charged. With. packages 0f. food. which be. eenvevedzto the upperendsyef Spaces. A between. plates in anysuitablemannen Valve E L3 is then turned; to the'. position in which4 it is shown in Eig; l3, Jsupplying-pressure=fluid to the upper ends. of the applicatorl cylinders,Y causing theV applicators to descend to their lowermost position,Y s uchas shown in Fig.v 111. As the applicators; descend theyI act as elevators forlowering the packages into positionbetween the plates. In movingdown, the applicators also actto'remove slush and previously applied anti-icing fluid to leave-a. clean freezing surface for the packages. When. theA applicators have reached their lowermost positionthey actuate trip levers ist, releasing; latchy |3IA and since` the outer ends of the cylinders t3v areA provided with pressure fluid through pipev |227, the outerplates 22 are moved inwardly against the packages to placethem under pressurebetweenv the plates. The freezing cyclesthenl commences and during this cycle the valve-may, b e tur-ned to the position in which it is shown in Fig. 11 to relieve stress on the applicator pistons and cylinders.

After the-food inthe packages has-been frozen the valve l-I may be moved to the positionV in which it is shown in Fig. 13 to supply fluidgto: the

inner end-s of the cylinders d3 and the lower ends utor pipe. is supplied with anti-icing fluid in thev mannerv heretofore described, which is sprayed onv the. surfaces ofv the plates. During upward 'rnovement of the appli-caters the lower and more flexible wiper 'H of each serves to evenly spreadv the anti-icingfluid over the surfaces ofthe plates. When the apphcators have reached their uppermost position, and before descending, it is preferable to wait a short interval of time to permit the anti-icing fluid to actupon any frost orice that may be present .to convert the same to slush or melt it before loading the, machine. again.`

When. this period. has.. passedthe operatonsmer befrepeatedfto aganleadthemachne, and dur-f ingf downward movement, of the, applicators. the; upper stiler wiper 'iof the applicator.- serves to. remove the anti-icingk fluid and any slush. from. the plates.

Although the invention has been particularlyshown and described, it is contemplated. thatl various changes and modifications may be made.: without departing from thescope of the inven-.. tionas indicated bythe following claims.v

Il claim:

1. A machine for the sharp freezing of food in packages comprising freezing plates disposed in parallel spaced relation and providing spaced parall-el highly heat conductive freezing surfacesbe,.-v tween which packages offeed tote frezen.- aref received, means for refrigerating said plates,v an

anti-icing uidapplicator member mountedfon movement between. each pair of plates, and-means.; for supplying said applicator members with anti-v icing uid during movement thereof in one direc?- tion, said applicator having a wiper. for remo/ving*- anti-icing nui-d and slush from said plates drilling-y movement inthe opposite direction,

2. A machine orthe sharp freezing of`V food.; in packages comprising vertically disposed-freezing plates disposed in horizontally spaced, relation and providing spacedA vertical highlyheat.

conductive freezing surfaces between which pack ages ofy food to be frozen are received, means for; refrigerating said plates, an anti-icing fluidl applicator member mounted for vertical movement between each pair of plates, andvmeansfor s upplying said applicator members with antificing iluid during movement thereof in one direction,l

said applicator having a wiper for removing anti@ icing fluid and slush from saidy platesr during movement in the opposite direction.

3. A machine for theY sharp freezing offood; in packages comprising vertically disposed` freezyv ing plates disposed in horizontally spaced Vrelation and providing spaced vertical highly heaticonductive freezing surfaces between which packages of food to be frozen are received, means forrefrigerating said plates, an anti-icing fluidV applicator member mounted for vertical movement? between each pair ofA plates, a package supporting surface on the upper edge of said applicator: member extending substantially the length of said plates, means for raising andV lowering said applicator members, and means for supplying said applicator members with anti-icing uid during upward movement thereof, said applicators each having a wiper for removing anti-icing fluid and slush from said plates during downward movement.

4. A machine for the sharp freezing: ofi' food?l in packages comprising vertically disposed freezing plates disposed in horizontally spaced relation and providing spaced vertical highly heati conductive freezing surfaces between which packages of food to be'frozen are received, means for refrigerating said plates, anti-icing fluid appli:

cator members mounted for vertical movement'v iiuid duringupward movement thereof,` said ap,.-

plicatorY members including a wiperfiorremoving. fluid and slush from thel surfaces of said platesV during downward. movement 0f; said; members..-

and means for moving the outer of said plates laterally inward when said applicator members are in normal lowered position.

5. A machine for the sharp freezing of food in packages comprising vertically disposed plates presenting oppositely disposed surfaces between which packages of food may be disposed, an elevator member adapted for vertical movement in each space between plates, said members being narrower than the width of the packages and being adapted to support a plurality of packages for loading and unloading thereof, means for raising and lowering said elevators, and means cooperatively associated with said raising and lowering means for moving said plates laterally into and out of pressure engagement with said packages.

6. In a machine for the sharp freezing of food in packages, a frame, a pair of vertically disposed plates constructed and arranged to be refrigerated and presenting opposed surfaces between which the packages of food may be disposed, means mounting said plates on said frame for limited vertical movement thereof, and an elevator member constructed and arranged for vertical movement between said plates for loading and unloading packages.

7. In a machine for the sharp freezing of food in packages, a frame, a pair of vertically disposed plates constructed and arranged to be refrigerated and presenting opposed surfaces between which the packages of food may be disposed, means resiliently suspending said plates on said frame, and an elevator member constructed and arranged for vertical movement between said plates for loading and unloading packages.

8. In a machine for the sharp freezing of food in packages, means providing a conduction freezing surface with which the packages may be brought into contact for freezing the contents, means for refrigerating said surface, means for periodically applying an anti-icing fluid to said surface, said means comprising an applicator constructed and arranged to traverse said surface, power means for actuating the applicator, and means for supplying the applicator with anti-icing uid.

9 In a machine for the sharp freezing of food in packages, a frame, a pair of vertically disposed plates constructed and arranged to be refrigerated and presenting opposed surfaces between which the packages of food may be disposed mounted on said frame for movement laterally toward and away from each other, an elevator member constructed and arranged for vertical movement between said plates, means for raising and lowering said elevator member, means for moving said plates laterally, and coordinating means constructed and arranged to operate the elevator raising and lowering means and the plate moving means in timed relation through a cycle of operation.

10. In a machine for the sharp freezing of food in packages, a frame, a pair of vertically disposed plates constructed and arranged to be refrigerated and presenting opposed surfaces between which the packages of food may be disposed mounted on said frame for movement laterally toward and away from each other, an elevator member constructed and arranged for vertical movement between said plates, hydraulic means for raising and lowering said elevator member, including a piston and cylinder means supporting said elevator, hydraulic means for moving said plates laterally, including a piston and cylinder means and linkage means connecting same with said plates, and coordinating means constructed and arranged to operate the elevator raising and lowering means and the plate moving means in timed relation through a cycle of operation.

11. In a refrigerating machine, a pair of spaced refrgerating plates providing opposed surfaces for engaging therebetween a package to be frozen, means mounting the plates for relative lateral and limited vertical movement, and package supporting means mounted for vertical movement between said plates and relative thereto.

12. In a refrigerating machine, a body, three vertically arranged refrigerated plates, including a center plate and two outer plates, mounted on the body in spaced parallel relationship for relative lateral movement and defining articlereceiving spaces therebetween, article-supporting members carried by the body for vertical movement relative to the plates, one in each of said spaces, means operatively associated with the outer plates to move them laterally towards and away from the center plate, and means operatively associated with the article-supporting members to move them vertically in said respective Spaces.

ISAAC H. POLK.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 175,291 Lount Mar. 28, 1876 1,527,562 Kolbe Feb. 24, 1925 1,817,890 Birdseye Aug. 4, 1931 1,822,089 Hall Sept. 8, 1931 1,928,755 Hall Oct. 3, 1933 1,977,373 Birdseye Oct. 16, 1934 1,998,431 Birdseye Apr. 23, 1935 2,029,175 Limpert Jan. 28, 1936 2,076,770 Dowell Aug. 13, 1937 2,124,110 Hall July 19, 1938 2,145,308 Jordan Jan. 31, 1939 2,315,768 Burnette Apr. 6, 1943 2,436,390 Kleist Feb. 24, 1948 

